The preexcitation syndrome: epidemiological and genetic study.

ABSTRACT

A sample of 4210 subjects of both sexes aged 35-54 years was examined, chosen at random from six regions of Croatia. An electrocardiogram at rest was performed in all subjects and changes analyzed by the Minnesota code. A short P-R interval together with a widening QRS complex and a delta wave was found in 0.05%, while 42 (1.0%) of the examinees had a short P-R interval, but only 0.21% were symptomatic. Three years after the first examination 0.06% of the subjects had preexcitation with a delta wave, and in one subject it appeared after three years. 0.35% of the subjects had a short P-R interval after three years but only 0.18% were symptomatic and in 22 (0.65%) it had disappeared in three years. After 13 years these subjects did not appear for an examination, and the short P-R interval did not appear in any of other subjects during this period. There were more short P-R intervals 3.22% in females and 1.96% in males, but 0.33% only were symptomatic. Antigens of the human leukocyte group A (HLA) system were analyzed in 46 patients the Wolff-Parkinson-White syndrome was found in 35, while 11 had the Lown-Ganong-Levine syndrome. Antigens of the HLA-A, HLA-B and HLA-DR locuses were determined by the microlymphocytotoxicity method. The results of the frequency of HLA system antigens were compared to the results of the control group of a Croatian population consisting of 175 people. There was an increased frequency of HLA-A9 and HLA-B5 (P = 0.026 and 0.0092) in the investigated population as a whole. The participation of HLA-A3 antigen was significantly less among patients (P = 0.03), while HLA-B14 antigen was not found in patients with preexcitation. Within 10 HLA-DR locuses, HLA-DR7 antigen was rather more frequently present, although this was not statistically significant (P = 0.173).